Cylinder hones



Feb. 26, 1957 J. T. CLARK CYLINDER HONES Filed April 2o, 195e lllll.- I N MN S ,a E a @N SAY.:

z',1sz,s7z CYLINDER HoNEs `lames T. Clark, Fort Morgan, Colo. Application April zo, 195s, serial No. 579,478

claims. (ci. s11s4.s)

The invention relates to a cylinder honing tool, such as illustrated in applicants copending application, Serial No. 527,064, ledAugust 8, 1955.

The improved tool is more particularly designed for honing the master hydraulic brake cylinders yof automotive vehicles but adaptable for use in honing the Iinternalfvvall of any -desired cylinder.

Hydraulic brake cylinders, after long use, develop smooth glazed spots on their interior wall against which it is difficult for the hydraulic piston `to make a satisfactory seal. The principal object of this invention is to provide a simple, light-weight, easily-used and accurate toolwh-i-ch can be used in the chuck :of an electric drill, and which =will rotate abrasive stones positioned on hone arms against the in-ner Wall of a cylinder to remove the glazed spots' yand provide a uniform matte surface against which piston will seal without leakage; and to provide means for bracing the hone arms against lateral bending tor displacement while the stones are being rotated in fri-ctional engagement with the cylinder Wall.

Another object of the invention is to provide a hon-ing tool which lcan becontracted to an exceedingly small diameter, for 'honing small cylinders, and expanded to relative large diameter, for honing large cylinders, and to provide effective means for maintaining the abrasive stones in resilient contact with the cylinder Wall.

Other objects and advantages reside in the detail `construction of the invention, which is designed for simplicity, economy, and eciency. These will become more apparent from the following description.

In the following detailed description of the invention, reference is had to the accompanying drawing which for-ms a part hereof. Like numerals refer to like parts in all views of the drawing and throughout the description.

In the drawing:

Fig. l is a side view of the improvedcylinder honing tool, illustrating it in the fully contracted position;

Fig. 2 is an enlarged, longitudinal section, taken on the center line of the honing extremity of the tool of Fig. 1, illustrating it in an expanded position;

Fig. 3 is a similarly enlarged cross-section, taken on the line 3 3, Fig. 2; and

Fig. 4 is a similar cross-section, taken on the line 4 4, Fig. 2.

The improved honing tool is supported from an axial shaft 10, the rear extremity of which is provided with external threads 11 upon which a knurled adjusting nut 12 is threaded. The rear extremity of the shaft is connected, through the medium of any suitable coupling de? "nited States Patent F e 2,782,572 latehted Feb. 26, 1957 on the forward extremity of the shaft I1t) in any desired manner. As illustrated, the disc 19 is provided with a square axial opening which is tted over a square, reduced extremity on the shaft 10. The disc. is maintained Ion the square extremity by upsetting the latter over the disc as shown at 20. The terminal disc 19 i-s formed with three .radially projecting lugs 21 spaced at 120 from each other.

A bearing spider 22, provided with radially projecting bearing ears 24, is slidably mounted on the shaft 10, i-n- `terrnediate the spring seat member 18 and the disc 19, and is maintained spaced from the spring s'eat member 18 by means of a suitable spacing sleeve 23. A relatively-thick, annular compression washer 33, formed of rubber or similar resilient material, surrounds the spacing sleeve 23.

A channel-shaped hone arm 25 is hingedly mounted on each bearing ear 24 through the medium of a suitable hinge rivet 26. The `hone arms 25 extend forwardly about the disc 19 and are so positioned that one of the lugs 21 on the disc 19 `will extend within the channel of each arm. A channel-shaped hone seat 27 is tfiltably mounted on the forward extrem-ity of each ofthe hone arms 25 upon a suitable pivot rivet 28. Each hone seat 27 is provided with an elongated honeastone 29 cemented to or other- Wise mounted thereon. vThe twosides of the channel of each hone arm 2S, adjacent the hinge pin 26, are provided with inclined edges 30 positioned to ride upon the periphery of the -disc 19, and each hone arm is provided with an inwardly inclined portion 31 positioned forwardly of the disc 19 which enables the hone .seats 27 to be brought into closely spaced .relation as illustrated in Fig. l. The top portion of the channel of each hone arm 25 extends rearwardly from the sides thereof to form a compression tab 32. The `tabs 32 extend rearwardly over and are in contact with the compression washer 33 and the latter acts lto constantly urge the three tabs `32 outwardly so as to constantly maintain the hone arms 25 resiliently in Contact with the periphery of the ydisc 19.

In use, the chuck stud 16 is placed in a drill chuck and the forward extremity of the tool is positioned within lthe cylinder to be honed. The nut 12 is then rotated forwardly on the threads 11, causing the bearing spider 22 t-o be forced forwardly on the shaft 10. This causes the inclined edges 30 of the hone arms 25 to ride outwardly against the periphery of the disc 19 so as to force the forward extremities of the hone arms radially outward from each other so as to bring the hone stones 29 into resilient contact with the inner lwall of the cylinder. During the honing operation, the tool is moved forwardly and rearwardly throughout the entire length of the cylinder until all glazed spots have been removed.

It is not necessary that the drill chuck be positioned in accurate axial alignment with the cylinder, since the ilexible shafting 14 will allow the tool to move independently `of the drill so as to align with the cylinder axis. Accurate cylinder alignment, however, is not critical, since the hone vseats 27 may freely tilt upon the hone arms 25 to resiliently conform to the position of the internal cylinder walls.

Any desired pressure may be placed on the hone stones by regulation of the nut 12, and when the honing operation has been completed, the nut 12 may be reversed to allow the hone stones to contract toward each other under the inuence of the expanding action of the compression washer 33 for withdrawal from the cylinder.

It will be noted that the disc 19 serves a dou-ble function. It serves as an expanding device for expanding the arms 25 as the spider is forced forwardly under the urge of the spring 17 and the lugs 21 thereon serve to rigidly brace the arms against lateral displacement under Ithe frictional drag of the stones 29.

While a specific form of the improvement has been described and illustrated herein, it is desired to be understood that the same may be varied, within the scope of the appended claims, without departing from the spirit of the invention.

Having `thus described the invention, what is claimed and desired secured by LettersPatent is:

1. A cylinder honing tool comprising: a shaft; a disc secured on the forward extremity of said shaft; a bearing spider slidably mounted on said 'shaft rearwardly of said disc; hone arms hingedly mounted on said spider and extending forwardly about and forwardly of said disc; a honing device tiltably mounted on the forward extremity of each arm; inclined portions on each arm adapted to contact said disc as said spider is forced forwardly, so that the incline of said portions will act to expand the forward extremities of said arms from each other; and means for urging said spider forwardly on said shaft to cause said disc to exert an expanding action on said arms.

2. A cylinder honing tool comprising: a shaft; a disc secured on the forward extremity of said shaft; a bearing spider slidably mounted on said shaft rearwardly of said disc; hone arms hingedly mounted on said spider and extending forwardly about and forwardly of said disc; a

-honing device tiltably mounted on the forward extremity of each arm; means for urging said spider forwardly on said shaft to cause said disc to exert an expanding action on said arms; and radial projections formed on said disc and engaging said arms so as to cause said arms to rortate with said disc.

3. A cylinder honing tool comprising: a shaft; a disc secured on the forward extremity of said shaft; a bearing spider slidably mounted on said shaft rearwardly of said disc; hone arms hingedly mounted on said spider and extending forwardly about and forwardly of said disc; a honing device tiltably mounted on the forward extremity of each arm; an inclined portion on each arm adapted to contact said disc as said spider is moved forwardly; a compression spring surrounding said shaft rearwardly of said beating spider; means forrtransmitt-ing the forward thrust of said spring to said spider; and a nut threaded on said shaft and acting' to urge the rear extremity of said spring forwardly to cause the inclined portions of said Aarms to be forced forwardly about said disc so as to separate the forward extremities of said arms from each other. Y

`4. A cylinder honing tool as described in claim 3 having means for urging said arms radially inward into contact with said disc.

5. A cylinder honing tool as described in claim 4 in which the means for urging the arms inwardly comprises: an annular, resilient member positioned between said spring and said spider; and'rearwardly projecting tabs formed on said arms and extending into peripheral contact with said resilient member so that when said arms are separated from each other, said tabs will compress said ,resilient member. i

References Cited in the iile of this patent UNITED STATES PATENTS .1,418,847 Stimson June 6, 1922 

